Clean up most clang warnings outside animator/

http://codereview.appspot.com/6464058/



git-svn-id: http://skia.googlecode.com/svn/trunk@5079 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/opts/SkBitmapProcState_opts_SSSE3.cpp b/src/opts/SkBitmapProcState_opts_SSSE3.cpp
index 3027688..e9dcc7f 100644
--- a/src/opts/SkBitmapProcState_opts_SSSE3.cpp
+++ b/src/opts/SkBitmapProcState_opts_SSSE3.cpp
@@ -415,7 +415,7 @@
     // (0, 0, 0, 0, 0, 0, 0, 0)
     const __m128i zero = _mm_setzero_si128();
 
-    __m128i alpha;
+    __m128i alpha = _mm_setzero_si128();
     if (has_alpha)
         // 8x(alpha)
         alpha = _mm_set1_epi16(s.fAlphaScale);